Isolation, Structure, and Absolute Configuration of a New Natural Insect Juvenile Hormone from Manduca sexta

Area of Science:

• Insect Endocrinology
• Organic Chemistry
• Biochemistry

Background:

• Corpora allata are crucial endocrine glands in insects, responsible for producing juvenile hormones that regulate development and reproduction.
• The tobacco hornworm moth (Manduca sexta) is a model organism for studying insect physiology and endocrinology.

Purpose of the Study:

• To isolate and identify juvenile hormones from organ cultures of Manduca sexta corpora allata.
• To characterize a newly discovered juvenile hormone and elucidate its chemical structure.
• To detail novel in vitro techniques for hormone production, isolation, and identification.

Main Methods:

• Organ culture of corpora allata from Manduca sexta.
• High-resolution liquid chromatography for purification of juvenile hormones.
• Incorporation of [(14)C]methionine to trace metabolic pathways.
• Chemical proof of structure for isolated compounds.

Main Results:

• Two juvenile hormones were isolated and purified: methyl (2E, 6E)-(10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (a new natural hormone) and methyl (2E,6E)-(10R,11S)-10,11-epoxy-3,7,11-trimethyl-2,6-tridecadienoate.
• [(14)C]Methionine was specifically incorporated into the methoxycarbonyl group of both hormones.
• Novel in vitro techniques were successfully employed for hormone production, isolation, and structural identification.

Conclusions:

• The discovery of a new juvenile hormone in Manduca sexta expands our understanding of insect hormone diversity.
• The developed in vitro techniques offer efficient methods for producing, isolating, and identifying insect juvenile hormones.
• This study provides significant insights into the biosynthesis and chemical nature of juvenile hormones in lepidopteran insects.